More than 120 schools were shut yesterday, along with two dozen libraries, 11 leisure centres and 22 neighbourhood offices.

The pay strike also hit refuse collections as binmen walked out.

Unions were protesting about a pay and grading review under which more than 4,800 workers will suffer wage cuts.

But MPs warned pointed out councils were obliged by law to carry out the review.

John Hemming (Lib Dem Yardley) said: "It is a bit odd for people to be striking when we are increasing the wages bill by £23 million.

"We are seeing some strange things, such as school assistants going on strike when their wages are set by school governing bodies rather than by the council.

"The law is the law and the council has to carry it out. Strike action could not change that, so it is hard to see the point of it."

And Lynne Jones (Lab, Selly Oak) said: "Councils across the country, whichever party controls them, are facing up to the fact that there will have to be losers and gainers from this process.

"One problem is that there seems to have been a lot of uncertainty about how it would work in practice, and the council could have done better there."

However, the strikers were backed by Khalid Mahmood (Lab Perry Barr) said: "I support the action that is being taken.

"The council needs to get control of the situation. They have had many years to plan for this, and yet the way it has been handled has been a disaster.

"I have had schools in my constituency complaining that they have taken advice from the council about how to introduce the changes, and the result has been a disaster.

"They are looking at turning to advice from outside the council."

Richard Burden (Lab Northfield) said he believed the strikers had been given no choice.

He said: "There are real grievances among the council employees and I just don't think from the conversations MPs had with the city council leadership that they have begun to appreciate how angry their employees are. They are in denial."